One of the rarest bats in Europe has begun colonising a new summer roost, created four years ago at an historic Roman site in Gloucestershire.

The lesser horseshoe bat has finally set up home in the roof of the visitor centre at Chedworth Roman Villa.

The project is part of a National Trust initiative to encourage and support the UK's declining bat population.

A spokesman said it was unique as it had been started from scratch and was not based on an existing roost.

'Bat flap'

Its success has been partly attributed to a specially-created "bat flap".

The covered hole in the gable end of the building is designed specially for lesser horseshoe bats, which prefer to fly straight into its roosts.

Other species land on the outer wall and crawl in via a narrow gap.

Without this sort of initiative, the numbers of lesser horseshoe bats will continue to decline

David Bullock, National Trust

More familiar pipistrelles and whiskered bats began settling in the new roost two years ago.

David Bullock, head of nature conservation at the National Trust and a trained bat-handler said: "Without this sort of initiative, the numbers of lesser horseshoe bats will continue to decline as they struggle to find suitable roosts and habitats.

"Bats are one of the key species for the National Trust and we are working to make sure that our buildings can effectively support colonies of them and other species throughout England, Wales and Northern Ireland."

The lesser horseshoe bat was once found throughout southern England and Wales.

Only about 14,000 remain, confined to south-west England and Wales.

The species' decline has been attributed to farming practices, disturbance and loss of roosts.